1. Field of the Invention
The present invention relates to a data input device for a computer and, in particular, to a device which enables inputting three-dimensional data into a computer.
2. Description of the Prior Art
As data input devices for computers, pointing devices, such as mice and digitizers, have been widely used cooperatively with keyboards. FIG. 15 is a diagram for explaining how to use a conventional mouse C as an example of the pointing devices. As shown in the figure, the mouse C is connected to a data input section of a computer B via a given mouse interface. Through the software in the computer B, displacement magnitudes of a pointer (or a pointed object) in the horizontal (x-axis) and vertical (z-axis) directions on the screen are controlled to correspond to displacement magnitudes of the mouse C in the leftward/rightward (x-axis) and forward/backward (z-axis) directions on the desk. Accordingly, when an operator moves the mouse C in a desired direction on the desk, the pointer displaces correspondingly on the screen of the computer B. However, the screen operation using the mouse C has been limited to be two-dimensional. This also applies to the other data input devices of the same kind, such as digitizers.
As shown in FIG. 16, in the simultaneous processing, such as multitask processing or multiwindow processing, windows a, b and c to be processed are displayed to as to overlap with each other on the screen. In this case, it is necessary to open the windows in sequence from the uppermost window. This complicates the operation and further tends to induce the operation errors when controlling a number of the windows. This has been resulted from the fact that the conventional data input devices can only achieve the two-dimensional data inputting, and thus the offered software should correspond to such two-dimensional data inputting.
On the other hand, in the CAD (computer aided design) employed in the construction machine designing or the like, the three-dimensional data inputting has been popular. However, since the conventional data input devices can only support the two-dimensional data inputting, functions provided by the CAD can not be fully utilized, thereby causing inconveniences in operation.